Preliminary observations on alcohol dehydrogenases in Comamonas terrigena that exhibit stereospecificity towards secondary alcohols.

Extracts of the cells of Comamonas terrigena, grown under a variety of different conditions, contain two distinct, constitutive, NAD-dependent alcohol dehydrogenase enzymes that can be separated by polyacrylamide-gel electrophoresis. One of the enzymes exhibits activity towards D-alkan-2-ols and primary alcohols and the other is active towards L-alkan-2-ols, symmetrical secondary alcohols and probably other positional isomers of secondary alcohols of the L-configuration. Methods for the individual assay of the two enzymes have been developed and have been used to define some of their general properties. Most of the substrates for these enzymes would not support growth of C. terrigena under the experimental conditions used and were relatively poorly oxidized by resting cell suspensions.